Semiconductor chips are used in a variety of electronic devices, such as, for example, computer equipment, where they can be employed as CPUs or video processors. The chips generate heat during operation, which can adversely affect performance of the chips.
International Patent Application Publication W001/25881 A2 (Asetek A/S) describes a computer system incorporating a cooling unit. The cooling unit uses conventional coolant that is being led from a compressor to a heat exchanger being in thermal contact with a component in the computer system generating heat, as example a central processing unit (CPU). The compressor is a low voltage compressor although the computer system has to have high voltage electrical power from the public electricity distribution net. By using a low voltage compressor the demands for power consumption and space may be limited. Also, it is possible to power the compressor from the built-in power supply of the computer system. In a preferred embodiment the heat exchanger being in thermal contact with the processing unit is enclosed in an insulated box. The box has openings for piping leading the coolant to and from the heat exchanger, and the box preferably also has a slot so that connection pins from the printed circuit board of the processing unit can protrude put through the box. Thereby the box can be attached to the motherboard by means of the connection pins. An alternative box has an orifice intended for abutting a base plate of the processing unit and has biasing means for holding the box onto a socket for the base plate and in abutment with the base plate.
Asetek Inc. markets a product called Vapochill™, promising vapor phase CPU cooling. The cooling system is, according to the advertising literature, based on use of a compressor to remove heat dissipated from a CPU. The vapor compression cycle is advertised to make the heat removal 10 times more efficient than water cooling and 50 times more efficient than air cooling.
U.S. Pat. No. 5,574,627 (Porter) describes resistive ink elements that are applied to the exposed surfaces of thin sections of thermal insulation provided to cool integrated circuit devices within a computer system. The insulation is made thinner than required to prevent the formation of condensation upon the exposed surfaces of the insulation in order to accommodate space limitations within the computer system. The resistive ink elements generate heat upon the application of an electrical current thereto to warm the exposed surfaces of the insulation to a temperature above the dew point of the ambient environment within the computer system, thereby preventing the formation of condensation on the surfaces of the insulation.
European Pat. App. No. 0489326 A2 (Hitachi Ltd.) describes an electronic computer cooling system having a cooling apparatus to cool an electronic computer and cooling members for thermally connecting semiconductor devices whose operating speeds are raised by cooling to a low temperature source of the cooling apparatus. Circuit boards onto which the semiconductor devices and the like constructing the electronic computer are mounted and the cooling apparatus such as a refrigerating apparatus and the like are compactly enclosed in a single casing. Or, the circuit boards and the cooling apparatus are compactly enclosed in separate detachable casings, respectively. Thus, a structure in which desired semiconductor devices can be certainly cooled by using the cooling members is obtained.